An arylglycidyl ether, which is a known starting material of an epoxy resin, has been industrially produced on a large scale and has been widely used in a variety of fields.
A method of producing an arylglycidyl ether that has been conventionally known can be represented by a method of obtaining a glycidyl ether by reacting a corresponding phenol with epichlorohydrin in the presence or absence of a catalyst under a basic condition. In this method, remaining organic chlorine compounds result in disadvantageously decreasing an insulating property when used in some applications, such as in electronics.
Therefore, direct epoxidation of an allyl ether of phenol by using an oxidizing agent has been studied. Patent documents 1 (JP-T-10-511722) and 2 (JP-A-60-60123) disclose methods of epoxidizing a diallyl ether of bisphenol A or a polyallyl ether of a novolak type phenol resin with hydrogen peroxide in an organic solvent, such as toluene, by using sodium tungstate and a phosphoric acid catalyst in the presence of a quaternary ammonium salt. However, these methods cannot be industrially carried out, since the tungsten compound must be used in a very large amount, and the rate of epoxidation is not sufficient.
Patent document 3 (U.S. Pat. No. 5,633,391) discloses a method of epoxidizing an olefin by bringing the olefin into contact with bis(trimethylsilyl)peroxide as an oxidizing agent in an organic solvent in the presence of a rhenium oxide catalyst. However, an expensive catalyst and oxidizing agent are necessary, and yield is insufficient in the case of phenylallyl ether.
Patent documents 4 (JP-A-7-145221) and 5 (JP-A-58-173118) disclose methods of allyl-etherifying a phenol novolak resin with an allyl halide followed by epoxidation with a peracid in an organic solvent. However, a peracid, which is highly dangerous, should be used.
Further, patent document 6 (JP-T-2002-526483) discloses a method of epoxidation with hydrogen peroxide in the presence of a titanium-containing zeolite catalyst, and a tertiary amine, a tertiary amine oxide or a mixture thereof. However, though this method is useful for a substrate organic material having a small molecular weight, the catalytic efficiency is poor with respect to a substrate having large molecular weight, such as phenyl ether. Therefore, the method cannot be applied.